Dc Current Function; 2-Wire Ohms Function - HP 3457A Service Manual

Operational Verification Tests
Rear lnput Operational Verification Tests (Standard Instrument) Cont'd
4-93. DC Current Function
-
Rear Terminal Offset Test
4-94. Equipment Required. This procedure does not require any test equipment.
1. Set the MP 3457A to the DC Current function (DCI), 3 mA range, and the number of digits dis-
played (DIGITS DISP) to six.
2. Use the Test Record to record the current offset readings on the 3 mA and 1 A ranges.
3. If any of the offset readings are beyond the limits specified in Table 4-30 and on the Test Record,
the instrument should be calibrated. Refer to Section V of this manual for calibration procedures.
4-95. 2-Wire Ohms Function
-
Rear Terminal Offset Test
4-96. Equipment Required. A low thermal short (copper wire) is required for this procedure.
3457A
I n p u t
Open
Open
1. Set the
HP 3457A t o the 2-Wire Ohms F~unction, 3 Kohm range and the number of digits displayed
(DIGITS DISP) t o six.
Table 4-30. DC Current Offset Test Limits (Rear Terminals)
1 y e a r t i m i t s
2. Use the Test Record t o record the offset readings for the 3 Kohm, 30 Kohm and 300 Kohm ranges.
3457A
Range
3 m A
30 m A
H i g h
+0.000104 m A
+00.00104 MA
3. If any of the offset readings are beyond the limits specified in Table 4-31 and on the Test Record,
the instrument should be calibrated. Refer to Section V of this manual for calibration procedures.
Low
-0.000104 m A
-00.00104 MA
3457A
Set Up
D C I
D C I
4-97. 4-Wire Ohms Function
-
Offset Test
3457A
I
n p u t
S h o r t
S h o r t
S h o r t
4-98. Equipment Required. A low thermal short (copper wire) is required for this procedure.
90 day L i m i t s
1.
Set the
HP 3457A to the 4-Wire Ohms Function (OHMF) and the number of digits displayed
(DIGITS DISP) to six.
H i g h
+0.000104 m A
+00.00104 m A
Table 4-31. 2-Wire Ohms Offset Test Limits (Rear Terminals)
3457A
Range
3 Kohm
30 Kohm
300 Kohm
Low
-0.000104 MA
-00.00104 m A
3457A
Set Up
OHM
OHM
OHM
90 day L i m i t s
0.000207 Kohm
00.00027 Kohm
000.0010 Kohm
1
y e a r l i m i t s
0.000207 Kohm
00.00027 Kohm
000.0010 Kohm